VPN Protocols

Hello guys!!
while im cheching the advanced firewall option of ZA,
I found that VPV Protocols are allowed by default.
My question is : could anyone tell me what are these protocols ? do i really need it to be allowed ? what if i uncheck this item ?
Thanks in advance.

Re: VPN Protocols

VPN stands for Virtual Private Networking. Various protocols are used to make this happen securely over an Internet connection. If a VPN connection were ever attempted, ZoneAlarm would alert you. If you do not use VPN then you can uncheck "allow VPN protocols" and "allow uncommon protocols at high security".